Growth, Development, and Immunizations

Development by age — the milestones tested most

Infant (0 to 12 months)

• 2 months — social smile, lifts head
• 4 months — rolls front to back, reaches for objects
• 6 months — sits with support, rolls both ways, transfers objects hand to hand, begins solid foods
• 9 months — sits alone, crawls, pincer grasp developing, stranger anxiety
• 12 months — pulls to stand, may walk, says a few words, birth weight roughly triples

Toddler (1 to 3 years)

• 15 months — walks alone
• 18 months — runs, uses a spoon, says many words
• 2 years — climbs stairs, two-word phrases, parallel play (plays beside other children, not with them)
• 3 years — rides a tricycle, speaks in sentences, toilet training usually complete

Preschool (3 to 5 years)

• Associative play, imaginative play
• Fears about body injury are common — use bandages, they matter to this age group
• Magical thinking — may believe illness is a punishment

School age (6 to 12 years)

• Cooperative play, rules matter
• Wants to be competent and productive
• Understands explanations — include them
• Privacy becomes important

Adolescent (13 to 18 years)

• Identity development
• Peers matter more than parents
• Body image is sensitive
• Wants independence and confidentiality
• Risk-taking behavior is common

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Preparing children for procedures — matched to age

The pattern: the younger the child, the shorter the notice. Long advance warning increases fear in young children.

Safety by age — a common question type

Infant: falls, choking on small objects, suffocation, car seat rear-facing, safe sleep on the back, water temperature.

Toddler: poisoning, drowning, falls, burns, car seat. Toddlers put everything in their mouths.

Preschool: playground injuries, street safety, drowning, stranger safety.

School age: bicycle helmets, sports injuries, water safety, seat belts.

Adolescent: motor vehicle accidents, substance use, sexual health, firearms, mental health.

The most common cause of injury changes with age — and the exam expects you to match the risk to the stage.

Immunizations

The general pattern:

• Hepatitis B — first dose at birth
• 2, 4, and 6 months — a series including DTaP, polio, Hib, pneumococcal, and rotavirus
• 12 to 15 months — MMR and varicella
• Boosters in the preschool years and again in adolescence
• Adolescents — Tdap booster, meningococcal, HPV

The exact schedule is set by national guidelines and is updated regularly. Always check the current schedule.

What the exam actually tests is the principles, not the dates:

Live vaccines — MMR, varicella, rotavirus, and live influenza.

Live vaccines are generally avoided in:

• Pregnancy
• Severely immunocompromised clients — including those on chemotherapy or high-dose steroids

Household contacts of immunocompromised people can usually still receive most vaccines — check current guidance.

Not reasons to delay a vaccine:

• A mild illness
• A low-grade fever
• Current antibiotic use
• Mild reaction to a previous dose

Reasons to hold or reconsider:

• A severe allergic reaction to a previous dose or a component
• Moderate to severe acute illness

Teaching parents: soreness, redness, and a mild fever are expected. Acetaminophen may be used as directed. Report a high fever, a severe reaction, or unusual crying.

The short version

• 6 months: transfers objects. 2 years: parallel play. 3 years: tricycle.
• The younger the child, the shorter the notice before a procedure
• Preschoolers fear body injury — bandages matter
• Adolescents: privacy and confidentiality
• Live vaccines: avoid in pregnancy and severe immunosuppression
• A mild illness is not a reason to delay a vaccine

Sources

• NCSBN. 2026 NCLEX-RN Test Plan. https://www.nclex.com/files/2026_RN_Test%20Plan_English-F.pdf

Immunization schedules are set by national guidelines and updated regularly. Always use the current schedule. Developmental milestone ages vary between sources.